Record of Chrono’s War: Apparently I’m Only the Strongest in Bed

Kurono Crawford, a noble of Cepheus Empire had a secret. It was that he came from a different world... modern Japan. Having the knowledge about the modern weapons and his sense of values, he was an existence almost like a cheat, aiming to be the Harem king. Abandoned by his superiors, left in command of the Empire's rejects consisting of demi-humans such as Minotaur's, Dwarfs, and Elves, and thrust into a position as head of a poor fiefdom, Kurono will do everything he can to rebuild and strengthen his forces and revitalize the land, aided in part by his knowledge of the other world.

On the day of his high school entrance exam, a boy named Crono is suddenly transported to another world. He became the commander of the demi-human army, won many great victories, and is feted as a lord. He gathers beautiful women one after another... A royal-road war story with battles, domestic politics, and sex! (Source: Kadokawa, translated) *Note: Starts from Chapter 9 of the prequel, with a new version of Chapter 10 and 11.*